Re: [Qemu-devel] [PATCH RFC] acpi: don't build acpi tables for xen hvm guests

[Stefano Stabellini]

CC'ing maintainers

On Tue, 25 Oct 2016, Wei Liu wrote:
> Xen's toolstack is in charge of building ACPI tables. Skip acpi table
> building if running on Xen.
> 
> This issue is discovered due to direct kernel boot on Xen doesn't boot
> anymore, because the new ACPI tables cause the guest to exceed its
> memory allocation limit.
> 
> Reported-by: Sander Eikelenboom <address@hidden>
> Signed-off-by: Wei Liu <address@hidden>

Hi Wei,
thanks for the patch. I think the right fix is to set

pcmc->has_acpi_build = false

for the xenfv machine and for the PC machine when accel=xen.

Thoughts?


> Cc: Anthony PERARD <address@hidden>
> Cc: Stefano Stabellini <address@hidden>
> 
> RFC because I'm not sure this is the best way to fix it.
> ---
>  hw/i386/acpi-build.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index a26a4bb..2cdff12 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -45,6 +45,7 @@
>  #include "sysemu/tpm_backend.h"
>  #include "hw/timer/mc146818rtc_regs.h"
>  #include "sysemu/numa.h"
> +#include "hw/xen/xen.h"
>  
>  /* Supported chipsets: */
>  #include "hw/acpi/piix4.h"
> @@ -2865,6 +2866,11 @@ void acpi_setup(void)
>          return;
>      }
>  
> +    if (xen_enabled()) {
> +        ACPI_BUILD_DPRINTF("Xen enabled. Bailing out.\n");
> +        return;
> +    }
> +
>      build_state = g_malloc0(sizeof *build_state);
>  
>      acpi_set_pci_info();
> -- 
> 2.1.4
>